The detection of occult HBV infection in patients with HBsAg negative pattern by real-time PCR method.

AIM: Diagnostic problems may be encountered in Hepatitis B virus (HBV) infections by serological tests and HBV DNA can be detectable in plasma and liver tissue while the HBsAg test is negative. This situation can be defined as occult or isolated Anti-HBc infections. Occult HBV infections may be divided into two categories by using hepatitis markers. One of them being that all hepatitis markers are negative and the other situation is having Anti-HBc +/- and Anti-HBs+patterns. These situations can be seen in isolated Anti-HBc cases. METHOD: In this study, we aimed to detect the ratio of occult HBV infections by investigating HBV DNA in four different groups. These groups are: (1) 20 isolated Anti-HBc positive individuals, (2) 23 individuals naturally immune to HBV infection, (3) 20 individuals with seronegative hepatitis markers and high ALT levels, and (4) 23 vaccinated individuals against HBV. In order to detect HBV DNA the real-time PCR kit (QIAGEN, Artus HBV RG PCR Kit, Germany) with high analytical sensitivity (≤3.8IU/ml) was used. RESULTS: The reliability of the molecular methods was assessed by increasing the quantitation standards of internal, external and also positive controls. No HBV DNA was detected in any of the 86 individuals consisting of four study groups. CONCLUSION: In conclusion, we did not detect occult HBV infection in our four study groups by using a high sensitivity real-time (RT) PCR method, while occult HBV infections with various frequencies were detected in other large, serial international studies in which highly sensitive analytical molecular methods were used. Although we also used a high standard molecular kit to detect occult HBV infections, we suggest that the reason for the absence of detection of occult HBV infections may be due to the small number of cases included in this study. However, it was assumed that the use of a nucleic acid amplification technology (NAT) with high analytical sensitivity in blood banks to prevent HBV transmission by blood transfusion is controversial due to both costs and diagnostic efficacy and for this reason we suggest that it will be useful to perform large serial studies regarding occult HBV infections in the future.

The importance of transmission time in HIV infections and an epidemiological prospective follow-up study for 1 year in the Marmara Region of Turkey.

It is important to detect recent and new HIV/1 infections and to take preventative measures in order to prevent rapid disease progression in AIDS and to decrease the incidence of infection. We aimed to detect long standing or recent HIV infections by determining transmission times for the cases in which first-time HIV/1 seropositivity were detected. The serum samples of 323 cases which were found to be seropositive by ELISA and Western-blotting were included in this study. The discrimination between long-term and recent HIV/1 infection was made by determining transmission-time with the Aware BED-EIA, HIV-1 incidence test (IgG capture HIV-EIA) tests. Ninety-six healthy blood donors who did not have a positive anti-HIV test and a chronic infectious disease for at least 1 year were included in this study as a negative healthy control group. In the discrimination of long-term and recent HIV/1 infections, only in vitro ODn values were used. The cases with normalized optical density (OD) (OD(specimen)/OD(calibrator))<0.8 by commercial kit were accepted as recent HIV infection (155 days history or seroconversion less than 6 months). The cases with ODn >1.2 were accepted as long-term HIV/1 infections (more than 155 days history or more than 6 months). The cases with ODn between 0.8 and 1.2 were accepted as "additional tests needed" cases. We detected recent HIV/1 infections (<6 months) in 60 (18.5%) out of 323 cases and long-term HIV/1 infections (>6 months) in 263 (81.5%) out of 323 cases. The most frequently encountered transmission route in long-term and recent HIV/1 infections was heterosexual sexual intercourse as 54 (50%) and 257 (97%), respectively. 63.3% of newly infected patients were married females and 65.3% of recently infected patients were males. In conclusion, the detection of the high ratio of long-term HIV/1 infection cases (81.5%) compared to recent infections (18.5%) suggested to us, that the long standing cases may have some activities related with transmission of HIV/1 in the past. The detection of higher HIV/1-infections in individuals which had heterosexual sex and also in married males suggested that this situation poses a very great threat for the health of society.

New approaches to in vitro diagnosis of hepatitis C infection a reason for post transfusion hepatitis: Diagnostic value of determination of hepatitis C virus core antigen.

In between the dates of February 2008-March 2009, by applying to Istanbul University CTF Microbiology and Clinical Microbiology Basic Sciences Branch and Duzen laboratories, 123 cases, where HCV RNA and anti-HCV positivity are identified with molecular (real-time PCR) and serologic (ELISA) methods as a positive control group, and 48 cases where HCV RNA and anti-HCV negativity are identified as a negative control group are established. The values of sensitivity, specificity, positive and negative approximation of recently developed HCV Core Ag (Abbott Diagnostics, Germany) kit are determined successively as 94.3%, 97.9%, 99.1%, 87%, 95.3% and 88%. Although the new HCV Ag assay is clearly not sensitive enough to replace HCV NAT it may serve as a valuable tool in the HCV diagnostic algorithm as it is able to pick up a great majority of anti-HCV and HCV RNA positive samples, thus allowing a timely and less expensive serological diagnosis of an active HCV infection. This may be an advantage for labs that do not have access to PCR easily.